Grade 9 Unit B: Curriculum Links | Print |

Unit B: Matter and Chemical Change
(Nature of Science emphasis)

Different materials have different properties. The ability to distinguish between different substances and make sense of their properties, interactions and changes requires development of ideas about chemical substance. In this unit, students are introduced to the formal study of chemical substances through laboratory investigations and introductory studies of chemical theory. In the laboratory, students observe and compare chemical substances and, with guidance on safety, investigate the properties of materials and the ways they interact. In conjunction with these studies, students are introduced to ideas about elements and compounds, and corresponding structural ideas of atoms and molecules. Theoretical ideas are introduced as means for explaining, interpreting and extending their laboratory findings; and include a general introduction to the periodic table, chemical nomenclature and simplified ways of representing chemical reactions.

This unit builds on ideas introduced in Grade 8, Unit B: Mix and Flow ofMatter, and introduces ideas that will be developed further in Science 10, Unit A: Energy and Matter in Chemical Change.

Focussing Questions:

What are the properties of materials?

What happens to them during
chemical change?

evidence do we have of chemical change?

ideas, theories or models help us explain that evidence?

Key Concepts

  • elements, compounds and atomic theory
  • reactants and products
  • chemical nomenclature (introductory treatment)
  • periodic table
  • conservation of mass
  • endothermic and exothermic reactions

STS and Knowledge Outcomes

Students will:

Investigate materials, and describe them in terms of their physical and chemical properties

illustrate and explain how our observations are guided by our initial ideas and by the tools and techniques that we use (e.g., describe how ideas such as "solubility" and "conductivity" can be used to guide observations; describe how the tools or techniques of study can affect what we observe)
investigate and describe properties of materials (e.g., investigate and describe the melting-point, solubility and conductivity of materials observed)
describe and apply different ways of classifying materials based on their composition and

- distinguish between pure substances, solutions and mixtures
- distinguish between metals and nonmetals
- identify and apply other methods of classification

identify conditions under which properties of a material are changed, and critically evaluate if a new substance has been produced

Students will:

Describe and interpret patterns in chemical reactions.

Identify evidence for conservation of chemical substance (e.g., identify and apply techniques for containing and comparing the quantity of reactants and products in a chemical reaction).

Describe examples of household reactions that involve chemical change. (Household Chemistry)

Distinguish between materials that react readily and those that do not.

Identify and evaluate dangers of caustic materials and potentially explosive reactions observe heat generated or absorbed in chemical reactions.

Identify examples of endothermic and exothermic reactions.

Identify conditions that affect rates of reactions (e.g., investigate and describe how factors, such as heat, concentration, surface area and electrical energy, can affect a chemical reaction)

Describe combustion, corrosion and other reactions involving oxygen.(oxidation and reduction) (chemical reaction )(types of reactions)

Identify the significance of these reactions for living things and inorganic processes (e.g. describe impacts of corrosion and identify measures to prevent corrosion)

Students will

Describe ideas used in interpreting the chemical nature of matter, both in the past and present, and identify example evidence that has contributed to the development of these ideas.

Distinguish between observation and theory

Provide examples of how models and theoretical ideas are used in predicting and explaining observations (e.g. note that kinetic molecular theory is used to explain why materials contract when cooled, but that other theoretical ideas are needed to explain why water expands as it cools from 4 to 0 Celsius)

Describe early ideas about the nature of substances and chemical change (e.g. describe early ideas about the nature of gases and their role in combustion and respiration)

Describe, illustrate and interpret early ideas about the nature of particles that underlie matter (e.g. describe and compare Dalton's billiard ball model of the atom, and Rutherford's planetary model)

Demonstrate an understanding of the periodic table, focusing on the first 18 elements, and use
the periodic table to identify the number of protons and electrons in each atom.

Sub Atomic Particles:
There are 3 types of sub-atomic particles.

  Protons - relatively large, have a positive charge.
  Neutrons - approx. same mass as proton, no charge.
  Electrons - small ( ~ 1/2000 mass of proton), negative charge.

Contains protons and neutrons
Makes up most of the mass of an atom.
 Small part of atoms volume.

Atomic Number

  The number of protons in the atom.
  The number of electrons = the number of protons, hence the overall charge in an atom is 0.

Mass Number

The number of protons in the nucleus + the number of neutrons in the nucleus, i.e. the total number of particles in the nucleus.


  Consists of atoms all having the same atomic numbers.
  There are 92 naturally occurring elements.

The Periodic Table:

The Periodic Table of Elements is how chemists organize all the Elements. The elements in any one column are said to be a family of elements. These are closely related element because they behave similarly in chemical reactions.

Atoms which have the same atomic number but different mass numbers.
i.e., belong to the same element but have different number of neutrons.

     e.g. 126C + 146C

     --> top number = mass number
     --> bottom number = atomic number

The Atomic Theory:
All matter is made up of tiny particles. (Difference between elements and compounds) The Atomic Theory states that
  • All matter is made up of tiny particles called atoms
  • Atoms of one element are the same.  When other atoms combine with other atoms they create molecules.
  • No ordinary means can destroy atoms or create atoms.

* Molecules contain identical atoms, Compounds contain atoms of at least two different elements.*
Information relating to the above material can be reached @ the following sites; *

The Natural Science Pages
Basic Atomic Information
Chemicool - Periodic Table
Chemical Elements . com
Element Tables

Links to a Visual Chemistry site.

Describe, explain and predict observable properties of elements (e.g., predict reactivity, conductivity and relative mass of different elements, based on their position in the table).

Recognize the need to describe and explain different ways that atoms combine to form molecules,
and the changes in properties that result.

Students will:

Apply simplified chemical nomenclature in describing elements, compounds and chemical reactions.

Identify/describe chemicals commonly found in the home, and write the chemical symbols
(e.g., salt [NaCl]; water [H20]; sodium hydroxide [Na0H] used in household cleaning supplies)

Interpret the combining ratios signified by chemical formulae.

Chemical Formulas:
Chemical Symbol is an abbreviation for compounds and elements either a capital letter or a capital letter followed by a lower case letter. Single symbols represent elements and combination symbols represent compounds. Chemical Formulas: The combination of symbols represents a particular compound. This indicates which elements are in a compound and in what proportion they represent.

Identify examples of combining ratios found in some common materials (Students should recognize that some materials have multiple combining ratios (e.g. CO, CO2, Fe203, Fe304)
[Prerequisite Skill: Grade 8 Mathematics, Number Operations, SO 151

Assemble or draw simple molecular models (e.g., construct models of some carbon compounds using toothpicks, peas and cubes of potatoes)

Describe familiar chemical reactions, and represent these reactions using word equations and chemical formulas.

Construct models of reactants and products (e.g. .... (Chem Sketch software available)
synthesis reaction
combination reactionc
combustion reactions
such as: Carbon + Oxygen ---» Carbon dioxide [C + 02 ---» C02];
corrosion reactions such as: Iron + Oxygen ---» Iron Oxide [Fe + 02 ---» Fe3 04];
replacement reactions such as: Zinc + Copper Sulfate ---» Zinc Sulfate + Copper
[Zn + CuSO4 ---» ZnS04 + Cu)
..... This reaction might be studied in connection with Unit D .....

Chemical Reactions- Changes, Chemical Change and Mass

There are two types of change. They include:
Physical change and chemical change. Physical changes are changes in which there is no new matter produced. ( e.g.. water can change state; freezing ,melting, boiling etc.) A chemical change or reaction is in which one or more new substances are formed. ( from properties different from those of the substances you started with) Examples include frying an egg, and metal rusting. There are certain clues to help you identify what change a substance has undergone. They are shown below.

    Clues for a chemical change:

  • -The substance has changed in colour.
  • -Heat or light is given off during the reaction.
  • -Bubbles or has has formed.
  • -Solid of a precipitate has formed.
  • -The change is very difficult to reverse.

Chemical Reactions:
Chemical changes are referred to as a chemical reaction. Any substance used up in the reaction is called a reactant. Any substance that is produced in a chemical reaction is a product. A complex description of a chemical reaction would include a detailed description of what happens, but the short way to describe it is to say what is used and what is produced. A word equation gives the names of all the reactants ( separated by a + ) followed by a ------> pointing to a product . e.g.

Iron +  Oxygen ----> Rust
----------------- -------
.........Reactants Product
[* Iron and oxygen produces Rust*]

Chemical Reaction Engineering

Chemical Reaction Demos

Reaction (Java Applet)

The Law of Conservation of Mass
In a chemical reaction, the total mass of the reactants is always equal to the total mass of the products.

Chemical Stuff

Edible/Inedible Experiments

Mass and Chemical Change:
Matter changes, but does the amount of matter also change? The earliest chemists ,who were called "natural scientists" did many experiments to answer questions. They were limited in 2 ways. First instruments did not allow them to make accurate measurements. Second until the atomic theory of matter was developed in 1808, they couldn't explain all their observations.

Reference for the above: CHEMystery

This web site has information on the different chemical changes that exist- Physical and Chemical Properties

If you are still having problems understanding the different changes take a look at this site-
Physical and Chemical Properties (Grade 8)

Chemistry (General) Miscellaneous Links

The Carbon Family

Rare Earth Elements

Periodic Table

The Alkali Metals

Trace Elements


The Native Elements Class

The Nitrogen Family